Database survivability under dynamic constraints

Summary The connection between static constraints satisfied by a database and its future evolution under dynamic constraints is investigated using the notions of survivability and survivability-closure. The static constraints considered here are functional dependencies (fd's). The dynamic constraints are restricted to commonly arising analogs of fd's, called dynamic fd's. The results provide new tools for the design of database schemes containing both static and dynamic constraints.Portions of this paper appeared in Dynamic Constraints and Database Evolution, Ph.D. Thesis, University of Southern California, 1983The author was supported in part by the National Science Foundation under grant number MCS-7925004     

From logic programming towards multi‐agent systems

In this paper we present an extension of logic programming (LP) that is suitable not only for the “rational” component of a single agent but also for the “reactive” component and that can encompass multi‐agent systems. We modify an earlier abductive proof procedure and embed it within an agent cycle. The proof procedure incorporates abduction, definitions and integrity constraints within a dynamic environment, where changes can be observed as inputs. The definitions allow rational planning behaviour and the integrity constraints allow reactive, condition‐action type behaviour. The agent cycle provides a resource‐bounded mechanism that allows the agent’s thinking to be interrupted for the agent to record and assimilate observations as input and execute actions as output, before resuming further thinking. We argue that these extensions of LP, accommodating multi‐theories embedded in a shared environment, provide the necessary multi‐agent functionality. We argue also that our work extends Shoham’s Agent0 and the BDI architecture. This revised version was published online in June 2006 with corrections to the Cover Date.     

Rapid behavior adaptation for human-centered robots in a dynamic environment based on the integration of primitive confidences on multi-sensor elements

This article presents a method for tele-operated mobile robots to rapidly adapt to behavior policies. Since real-time adaptation requires frequent observations of sensors and the behavior of users, rapid policy adaptation cannot be achieved when significant data are not differentiated from insignificant data in every process cycle. Our method solves this problem by evaluating the significance of data for learning based on changes in the degree of confidence. A small change in the degree of confidence can be regarded as reflecting insignificant data for learning (that data can be discarded). Accordingly, the system can avoid having to store experience data too frequently, and the robot can adapt more rapidly to changes in the user’s policy. In this article, we confirm that by taking advantage of a significance evaluation not only of proposition of behavior, but also of each proposition of each piece of sensor-level data, a robot can rapidly adapt to a user’s policy. We discuss the results of two experiments in static and dynamic environments, in both of which the user switched policies between “avoid” and “approach.”     

“Those found responsible have been sacked”: some observations on the usefulness of error

Erik Hollnagel’s body of work in the past three decades has molded much of the current research approach to system safety, particularly notions of “error”. Hollnagel regards “error” as a dead-end and avoids using the term. This position is consistent with Rasmussen’s claim that there is no scientifically stable category of human performance that can be described as “error”. While this systems view is undoubtedly correct, “error” persists. Organizations, especially formal business, political, and regulatory structures, use “error” as if it were a stable category of human performance. They apply the term to performances associated with undesired outcomes, tabulate occurrences of “error”, and justify control and sanctions through “error”. Although a compelling argument can be made for Hollnagel’s view, it is clear that notions of “error” are socially and organizationally productive. The persistence of “error” in management and regulatory circles reflects its value as a means for social control.     

Rudolph M. Schindler—Proportion,Scale and the “Row”

Jin-Ho Park interprets Schindler’s “reference frames in space” as set forth in his 1916 lecture note on mathematics, proportion, and architecture, in the context of Robinson’s1898–99 articles in the Architectural Record. Schindler’s unpublished, handwritten notes provide a source for his concern for “rhythmic” dimensioning in architecture. He uses a system in which rectangular dimensions are arranged in “rows.” Architectural examples of Schindler’s Shampay, Braxton-Shore and How Houses illustrate the principles.     

Dynamic group communication

Group communication is the basic infrastructure for implementing fault-tolerant replicated servers. While group communication is well understood in the context of static groups (in which the membership does not change), current specifications of dynamic group communication (in which processes can join and leave groups during the computation) have not yet reached the same level of maturity. The paper proposes new specifications – in the primary partition model – for dynamic reliable broadcast (simply called “reliable multicast”), dynamic atomic broadcast (simply called “atomic multicast”) and group membership. In the special case of a static system, the new specifications are identical to the well known static specifications. Interestingly, not only are these new specifications “syntactically” close to the static specifications, but they are also “semantically” close to the dynamic specifications proposed in the literature. We believe that this should contribute to clarify a topic that has always been difficult to understand by outsiders. Finally, the paper shows how to solve atomic multicast, group membership and reliable broadcast. The solution of atomic multicast is close to the (static) atomic broadcast solution based on reduction to consensus. Group membership is solved using atomic multicast. Reliable multicast can be efficiently solved by relying on a thrifty generic multicast algorithm. Andrée Schiper graduated in Physics from the ETHZ in Zurich in 1973 and received the PhD degree in Computer Science from the EPFL (Federal Institute of Technology in Lausanne, Switzerland) in 1980. He has been a professor of computer science at EPFL since 1985, leading the Distributed Systems Laboratory. During the academic year 1992–1993, he was on sabbatical leave at the University of Cornell, Ithaca, New York, and in 2004-2005 at the Ecole Polytechnique near Paris. His research interests are in the area of dependable distributed systems, middleware support for dependable systems, replication techniques (including for database systems), group communication, distributed transactions, and, recently MANETs (mobile ad-hoc networks). From 2000 to 2002, he was the chair of the steering committee of the International Symposium on Distributed Computing (DISC). He has taken part in several European projects. He is currently a member of the editorial board of Distributed Computing, and of IEEE Transactions on Dependable and Secure Computing.     

Rudolph M. Schindler—Space Reference Frame,Modular Coordination and the “Row”

While Rudolph Schindler’s “space reference frame” is becoming better known, its relationship to the “row” has only been recently investigated. The theory of the “row” counters traditional proportional notions, many of which are derived from the principle of geometric similitude a principle which is mostly represented in architectural drawings by regulating lines and triangulation.     

Business cycle and corporate failure in France: Is there a link?

The aim of this paper is to extract cyclical factors from companies’ data possibly used in the construction of the scores by the Bank de France and from these scores themselves. The constraints are those of a database including a large number of variables and companies but over a relatively short period. The method chosen is the “principal components method” adapted by Bai and Ng (2000, 2001) in the context of large N and limited T. Later, these factors may be used to take into account the business cycle in the application of scores. An erratum to this article can be found at     

Yes,She Was!

Ford’s “Helen Keller Was Never in a Chinese Room” claims that my argument in “How Helen Keller Used Syntactic Semantics to Escape from a Chinese Room” fails because Searle and I use the terms ‘syntax’ and ‘semantics’ differently, hence are at cross purposes. Ford has misunderstood me; this reply clarifies my theory.     

Management: a scientific discipline for humanity

This paper proposed a new concept of management: Managing According to Reason (MR). Since “manage” means to lead, plan, organize and control, and “reason” means to understand the law of the development of objects being managed, this new concept is an integration of the two elements of “managing” and “reason”. MR studies the contradictory relationship between “managing” and “reason”, and considers how such a relationship changes and develops. MR is an integration of the disciplines of management, philosophy, natural science, engineering technology, and social science. We believe the MR is a comprehensive scientific discipline that will greatly benefit humanity. Since “management” cannot work without power, while “reason” relies on science, MR is an integration of power and science. Power is MR’s assurance, and science is MR’s basis. We believe that MR will play a major role in twenty-first century.     

Direct and indirect gradient control for static optimisation

1 Introduction Chemical process plants are always controlled in dif- ferent layers. For example, several local control layers are designed to maintain local controlled variables at the desired operating point whilst a plantwide optimi- sation layer is responsible for adjusting the setpoint to the local layers according to di?erent situations (dis- turbances). Traditionally, these two layers are designed separately for di?erent (economic and dynamic) objec- tives although they need working toge…     

Dialogue Abner Shimony–Shimon Malin

Malin proposes a solution to some of the conceptual problems of the foundations of quantum mechanics within the framework of Alfred North Whitehead’s “Philosophy of Organism”. Standard quantum dynamics, governed by the time-dependent Schr?dinger equation, does not provide for the reduction of superpositions of physical states and hence does not account for occurrence of observational data. If consciousness is invoked to explain the results of measurements, it would appear that quantum mechanics is given an anthropocentric interpretation. Reduction of superpositions is achieved without anthropocentrism, according to Malin, by accepting Whitehead’s ontology of “actual occasions”, which are protomental entities independent of and presumably antedating human beings. Furthermore, Whitehead’s philosophy has the great virtue of offering a plausible solution to the profound problem of relating minds to material systems. Shimony is sympathetic to Whitehead’s world view, but with the reservation that it leaves an immense unexplained and unexplored gap between the conjectured “experience” of actual occasions and the high level experience of the human mind.QUPON/QIPC Special Issue     

A fuzzy extension of the XPath query language

Today the current state of the art in querying XML data is represented by XPath and XQuery, both of which rely on Boolean conditions for node selection. Boolean selection is too restrictive when users do not use or even know the data structure precisely, e.g. when queries are written based on a summary rather than on a schema. In this paper we describe a XML querying framework, called FuzzyXPath, based on Fuzzy Set Theory, which relies on fuzzy conditions for the definition of flexible constraints on stored data. A function called “deep-similar” is introduced to replace XPath’s typical “deep-equal” function. The main goal is to provide a degree of similarity between two XML trees, assessing whether they are similar both structure-wise and content-wise. Several query examples are discussed in the field of XML based metadata for e-learning.     

A Term Project: Creating a Geometry Cathedral

Michael Serra’s high school classroom became a “geometry Cathedral” when students created panels with a stained-glass effect for the windows in the classroom. Projects like this can convert “math atheists” into “geometry believers”.     

An anytime revision operator for large and uncertain geographic data sets

 The environmental data are in general imprecise and uncertain, but they are located in space and therefore obey to spatial constraints. The “spatial analysis” is a (natural) reasoning process through which geographers take advantage of these constraints to reduce this uncertainty and to improve their beliefs. Trying to automate this process is a really hard problem. We propose here the design of a revision operator able to perform a spatial analysis in the context of one particular “application profile”: it identifies objects bearing a same variable bound through local constraints. The formal background, on which this operator is built, is a decision algorithm from Reiter [9]; then the heuristics, which help this algorithm to become tractable on a true scale application, are special patterns for clauses and “spatial confinement” of conflicts. This operator is “anytime”, because it uses “samples” and works on small (tractable) blocks, it reaggregates the partial revision results on larger blocks, thus we name it a “hierarchical block revision” operator. Finally we illustrate a particular application: a flooding propagation. Of course this is among possible approaches of “soft-computing” for geographic applications. On leave at: Centre de Recherche en Géomatique Pavillon Casault, Université Laval Québec, Qc, Canada – G1K 7P4 Université de Toulon et du Var, Avenue de l'Université, BP 132, 83957 La Garde Cedex, France This work is currently supported by the European Community under the IST-1999-14189 project.     

Physical Limits on Self-Replication Processes

Using few very general axioms which should be satisfied by any reasonable theory consistent with the Second Law of Thermodynamics we argue that: a) “no-cloning theorem” is meaningful for a very general theoretical scheme including both quantum and classical models, b) in order to describe self-replication, Wigner’s “cloning” process should be replaced by a more general “broadcasting”, c) “separation of species” is possible only in a non-homogeneous environment, d) “parent” and “offspring” must be strongly correlated. Motivated by the existing results on broadcasting which show that only classical information can self-replicate perfectly we discuss briefly a classical toy model with “quantum features” — overlapping pure states and “entangled states” for composite systems.     

Adaptive guaranteed estimation based on information provided by a set of “Relative” objects

Estimation algorithms for the state of an object based on “relative” objects information are proposed, under conditions of disturbances affecting the object and errors caused by incomplete and inaccurate measurements of the object’s vector. Information on disturbances and measurement errors is considered known up to some given sets. If the path of the object’s motion is changed, it is suggested to use information provided by a group of similar objects for identifying model of the object’s further motion.     

Opinion helpfulness prediction in the presence of “words of few mouths”

This paper identifies a widely existing phenomenon in social media content, which we call the “words of few mouths” phenomenon. This phenomenon challenges the development of recommender systems based on users’ online opinions by presenting additional sources of uncertainty. In the context of predicting the “helpfulness” of a review document based on users’ online votes on other reviews (where a user’s vote on a review is either HELPFUL or UNHELPFUL), the “words of few mouths” phenomenon corresponds to the case where a large fraction of the reviews are each voted only by very few users. Focusing on the “review helpfulness prediction” problem, we illustrate the challenges associated with the “words of few mouths” phenomenon in the training of a review helpfulness predictor. We advocate probabilistic approaches for recommender system development in the presence of “words of few mouths”. More concretely, we propose a probabilistic metric as the training target for conventional machine learning based predictors. Our empirical study using Support Vector Regression (SVR) augmented with the proposed probability metric demonstrates advantages of incorporating probabilistic methods in the training of the predictors. In addition to this “partially probabilistic” approach, we also develop a logistic regression based probabilistic model and correspondingly a learning algorithm for review helpfulness prediction. We demonstrate experimentally the superior performance of the logistic regression method over SVR, the prior art in review helpfulness prediction.     

The genesis of “The Visual Computer”

A brief history and the prospects of “The Visual Computer”and “The Visual Computer: An International Journal” are presented solely to foster future research on the visual computer. It is still in its infancy, and the author’s view is based on his own limited experiences, and hence is prone to mistakes.     

Structured large margin machines: sensitive to data distributions

This paper proposes a new large margin classifier—the structured large margin machine (SLMM)—that is sensitive to the structure of the data distribution. The SLMM approach incorporates the merits of “structured” learning models, such as radial basis function networks and Gaussian mixture models, with the advantages of “unstructured” large margin learning schemes, such as support vector machines and maxi-min margin machines. We derive the SLMM model from the concepts of “structured degree” and “homospace”, based on an analysis of existing structured and unstructured learning models. Then, by using Ward’s agglomerative hierarchical clustering on input data (or data mappings in the kernel space) to extract the underlying data structure, we formulate SLMM training as a sequential second order cone programming. Many promising features of the SLMM approach are illustrated, including its accuracy, scalability, extensibility, and noise tolerance. We also demonstrate the theoretical importance of the SLMM model by showing that it generalizes existing approaches, such as SVMs and M⁴s, provides novel insight into learning models, and lays a foundation for conceiving other “structured” classifiers. Editor: Dale Schuurmans. This work was supported by the Hong Kong Research Grant Council under Grants G-T891 and B-Q519.